211112121991 has 2 divisors, whose sum is σ = 211112121992. Its totient is φ = 211112121990.

The previous prime is 211112121977. The next prime is 211112122079. The reversal of 211112121991 is 199121211112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 211112121991 - 2¹¹ = 211112119943 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211112121191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105556060995 + 105556060996.

It is an arithmetic number, because the mean of its divisors is an integer number (105556060996).

Almost surely, 2^211112121991 is an apocalyptic number.

211112121991 is a deficient number, since it is larger than the sum of its proper divisors (1).

211112121991 is an equidigital number, since it uses as much as digits as its factorization.

211112121991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 648, while the sum is 31.

The spelling of 211112121991 in words is "two hundred eleven billion, one hundred twelve million, one hundred twenty-one thousand, nine hundred ninety-one".